Naoki Morishima

Single-phase STATCOM for feeding system of Tokaido Shinkansen

In the Tokaido Shinkansen, SVCs (static var compensators) have been installed at the single-phase feeder side in select substations to reduce the descent in the feeding voltage. A single-phase STATCOM (static synchronous compensator), called an RPC (railway static power conditioner), consists of a back-to-back converter whose AC terminals are connected to the two power systems of a Scott transformer. When the two terminals of the RPC are connected to a single power system, the RPC can operate as an SVC. RPCs can both control the feeder voltage and equalize the unbalanced power flow between the two singlephase power systems. In this paper, we present the simulator test and field test results of the RPCs installed in select substations of the Tokaido Shinkansen.

450MVA GCT- STATCOM for stability improvement and over-voltage suppression

The worlds largest 450MVA STATCOM using GCT(Gate Commutated Turn-off) thyristor is designed for installation plan at Toshin substation of Chubu Electric Power Co. in Japan. The main purposes of the STATCOM are improvement of the power system stability and suppression of AC over-voltage occurred after route outage fault at heavy load condition. This paper describes the determination procedure of specification requirements and a system configuration. Also this paper reports simulation results for route outage fault and line-to-ground fault at nearby location of the STATCOM. STATCOM performance is verified by these simulation results.

Coordinated Voltage Control and Continuous Operation of the 80MVA STATCOM under Commercial Operation

We have newly developed an 80 MVA GCT STATCOM for the Kanzaki substation of the Kansai Electric Power Co., Inc. It started commercial operation in June, 2004. The main purpose of the STATCOM is to maintain voltage during single circuit connection of source to the substation resulting from an AC system fault in order not to break down load system of the substation. The developed STATCOM has three distinctive features: (1) a high-efficient, compact and AC filter-less system using multistage three-level GCT converter and customized PWM; (2) a coordinated voltage regulator with tap control of main transformers; and (3) a continuous operation from a single phase-ground fault through reclosing of the faulted circuit by limiter adjustments of the reactive current reference. This paper describes characteristics of the coordinated voltage and validity the continuous operation during AC system faults using data of commercial operations and the simulation results.

Harmonics control of the 20 MVA PWM inverter fed LSM drive system for the Yamanashi Maglev Test Line

This paper deals with harmonics control of a 20 MVA PWM inverter-fed LSM drive system for the Yamanashi Maglev Test Line in Japan. Contents include: (1) maintaining current control performance and compensating the resonant characteristics of the LSM load with a high-power filter; (2) developing a novel PWM control method, in order to reduce the lowest and/or second order carrier harmonics caused by asymmetrical PWM multiplication; and (3) reducing the inductive interference caused by zero sequence harmonics with a common-mode reactor.